Boring fixture



July 12, 1960 R. F. oNsRuD 2,944,445

BORING FIXTURE RUDOLPH F ONSRUD t f4 Mm ATT'Ys July 12, 1960 Filed Nov.26, 1958 R. F. oNsRuD BORING FIXTURE RUDOLPH F. ONSRUD 2,944,445 BoRlNGFIXTURE Rudolph F. Onsrud,.Chicago, Ill., assignor to Onsud MachineWorksjlnc., Niles, Ill.

This invention relates to a fixure for sequentially boring a pluralityof bores in a workpiece. More in particuf l-ar this invention relates toa Xture for sequentially boring a pair of bores adjacent to'each otherin a single cycle operation.

In the mass production of certain parts such as some components used incamera and projector ,assemblies,ra given part requires numerous machineoperations that are performed in sequence beginning with rough blank tothe finished part. Oftentimes to conserve production costs theblanks'o'r workpiecesA are inserted in a rotatable turret. The turretrotates a predeterminedangular displacement carrying the workpiec'eto.ai'rst stage and stops wherein the.vvorkpiece is positionedY to receivej its first machiningoperation(l `As soonfasf the rstfstage machineoperation hasA` ,been completed-the turret again rotates'y apredetermined angular displacement and again stops whereinftheworkpieceis vrpositioned "tojrel ceive its second machining operation. InAsimilar manf ner' the( turretis progressively rotated. to eachsucceedin'g stage yand finally after4 the last stageoperation has beenperformed the finished part is removed from the turret. By such meansseveral Vparts'are receivingydifferentimachining operationssimultaneously andjin general, requires no moreV than one operator'whose duty is toV insert blank workpieces on-the initial position andremove Vfinished parts simultaneously. gflfhe movement of the turret toeffect each ofthe various stage oper`ations is usuallyV accomplishedbyautomatic means operating-*ina timed cyclic relation. Yj 1 IParticularly in, cases Where the., requirements of Y-the product partprovidesy for a pair of .bores inclose spaced relation` theycannot :bedrilled simultaneously :inta one Thus in such means theV elementisabout; Figure l. Q

ice

lpreceding objectsv wherein the workpiece is maintained stationaryVduring the boring operation. *t

Anotherv important objectv of this invention is to provide a low costefficient means for boring a plurality of bores'sequentially intastationary workpiece in accordance with the preceding objects.

These and other desirable and important objects inherent in andencompassed by the invention will-be more readily understood from theensuing description, the appended claims Vand thefannexed drawingswherein: n

lFigure 1 is a plan view of the mechanism of this invention illustratingthe position of its components at the start of a boring cycle. 'i

AFigure/2 is similar to `rl-ligure l villustrating the position of thecomponent parts when the irst bore infthe workpiece has beenaccomplished and the boring element is about to beginretractive-movement. i

Figure 3 is similar to 'Figures l and 2 showingthe position of thecomponent partswwhen the boringelement has been withdrawn from Ythe irstbore in the workpiece and has moved transversely toa second position.. yY "Y Figure4 is vksimilar tothe preceding figures and shows the positionof the component parts when the second bore -in .ther Workpiecedhas beenaccomplished and the boring to retracty tojthe position illustrated inWith continuedvreference sito the drawings; the numeral 10 generallyindicates a` xtilrrev comprising La; preferred embodimentofthis.invention.,f1`hefixture' 10 is pro.-

`vided with abase 11 Vvvhich'may forfconveniencebe a metalplate such asiron or steel.l The base lljis'provided with aj longitudinally disposedtrack-12 whichi'may bein theV form of a recess or slot in'the base l11having parallel spaced kguide walls 13 'and`14. VSlidably disposed Vinlthe kforward portion of the track 12 is Ka driven member generallyindicated at 15. =If desired the guide walls 13l and 14 of the base 11may be undercut and the sliding edge (not shown)may be litted to matchin a conventional manner sothat the driven member 15 is confined to .thetrack 12. This/serves to. prevent the driven member'lS from moving inany direction except ystage operation Vbecausethe diameters ofthe chucksemby -the average of the diameters of thej two vassociated l chucks. Y

Y The present invention is particularly directed t0; over- Y cominglthey above described .limitait-ioni` .vt/hereby,vv two, l boreszmfor.example, cany b e made tangentially tof-feach other ina single stageoperation. .Itfis therefore-a prime object'of thisyinventionto provide a:means for drilling or yboring a plurality of bores in a workpiece in`close proximity to eachother in a singlelstage operation@Y inventionis-to provide manstfforfbong a :pluralityfcf bcressaccordingtofthe vfvlongitudinally.

Vment 28 for'- rotation therewith.'

. In order to prevent retractive or rearward movement of the drivenmember 15 beyond aapredetermined'posi.- tion, vthe. reason for `whichwill become apparent'later,

'stop'imeans are provided on thefbase 11 which mayl for v convenience bea pair of stop pins 16/and 17.

ings. VTheblock 15 is provided --with arearward `eX tending projectionor lug 20 rigidlyfcnnected thereto.

fThe rearward end of the lug 20 is provided with apair of laterallydisposed shoulders`21 and 22 as best illustratedj in Figures Y3 'and 4..A pivot pin 23 is also positioned on the lug 20 for a purpose to bedescribed later.

Positioned for transversemovement in the groove 19 ofthe block 18 isa'motor, ygenerally indicated kat 24,

mounted on a plate 25 slidable in the groove 19.y 'Thus' the motorl 24and its associated mounting plate 25 is movable with respect tothe block18 in-A a transverse di-v 'i rectio'n which movement may belimited bythe-slot 68 in theblock 18.` The motor k24'is providedwith a rotatableelement 26 having its vaxis of rotation positioned longitudinally. Theforward end of the rotatable element 26 is provided with conventionalchuck or clampingmeans A27V adapted to secure a drillo'r boring ele-'Ihe construction of the motor mechanism may be conf;

ventional incharacter such'as-of-the electric type or'pneui 3 Y matictype. The pneumatic type is preferred because in the case where verysmall bores are to be made using the fixture of this invention, therotative speed of the bo'ring element 28 may be in the order of 80,000revolutions 'per minute which is desirable for certain types of operation. A provided source of energy is connected to the motor 24 inoperable relation such as by a flexible hose (not shown) in aconventional manner. Thus means have been described for rotating theboring element 28. 4Mounted on the rearward end of the base 11 is apower means which may for convenience be a double-acting fluid cylindergenerally indicated at 29. The cylinder is of conventional typecomprising a casing 30 having a piston 31 slidably in a longitudinaldirection therein. Connected to the piston 31 is a reciprocable workmember 32. The cylinder is operatively connected to a source of iluidunder pressure such -as compressed air with conventional co'ntrol meansinterposed to pressurize selectively one of the chambers 33 or 34through one of the associated uid conduits 35 or 36 while exhaustingfluid from the other of the chambers and its associated conduit.Although a two-way acting cylinder 29 is illustrated a single actingcylinder having a spring positioned in the chamber 33 for retracting thework member 32Vw`nen de-energized may also be employed. In fact any typeof a power device which is adapted to reciprocate the work member 32 maybe employed in rthis invention.

In the rearward portion of the track 12 is disposed in slidable relationa driving member generally indicated `at 37. The driving member 37 isrigidly connected to the work member 32 for recipro'cation on the track12. Similarly as before the driving member 37 may be fitted to the track12 to confine the movement thereof inV a longitudinal direction. Thedriving member 37 may comprise a metal carrier 38 having a projection 39eX- tending rearwardly on one side. The projection 39 is provided with atrip plate 40 'secured thereto by screws 41 and 42 in a longitudinallyadjustable relation. A 'conventional electric micro switch generallyindicated at 43 is mounted on the rear portion of the base 11 positionedfor operative engagement of the actuating lever 44 thereof with the tripplate 40.

The carrier 38 of the driving member 37 is provided on the forwardportion thereof with a shift cam 45 for a purpose to be described later.

A pair of fingers 46 and 47 are pivotally connected to the carrier 38 bypins 48 and 49 respectively and extending forwardly as shown in thedrawings. Positioned on the forward end portion of the linger `46 is anotch S as best shown on Figures 3 and 4. The notch 50 is positioned .toengage the shoulder 21 of the lug 20 in forwardly driving relation asshown in Figures l and 2. Similarly the finger 47 .is also provided witha notch 51 on the forward portion thereof positioned to engage theshoulder 22 of the lug 20 in forwardly driving relation as illustratedin Figures *3 and 4. The notch 51 is positioned rearwardly with respectto the notch 50 for a purpose also to be described later.

On the forward end portion of the finger 46 isa cam 52 having itsactuating surface angularly disposed.v

Mounted on the base 11 is a cam pin 53 positioned to engage the cam 52when the driving member 37 mo'ves the finger 46 forwardly apredetermined distance to a first release position. The engagement ofthe cam 52 with the earn pin 53 causes the finger `46 to move arcuatelyin a clockwise direction about the pivot 48 which disengages the notch50 from the shoulder 21 thus terminating the forward movement of thedriven member 15.

In similar manner as that just described `the finger 47 on the forwardend portion thereof is a cam S4 having lts actuating surface angularlyvdisposed in the opposite direction with respect to cam ,52. Mounted onthe base 11 is another earn pin 55 positionedto engage theV cam 4 54when the driving member moves the linger 47 for# wardly a predetermineddistance to a second release position. The engagement o'f the carn 54with the cam pin 55 causes the finger 47 to move arcuately in acounterclockwise direction about the pivot 49 which disengages the notch51 from the shoulder 22 thereby again terminating the forward movementof the driven member 15.

As a suitable means for urging the fingers 46 and 47 toward engagementof their respective notches 50 and 51 with the shoulders 21 and 22 atension spring 56 is anchored at one end thereof to the finger `46 andthe other end being anchored to the finger'47 (as shown in Figure 1.

Pivotally mounted on the pin 23 of the lug 20 is a shift arm 57. On therearward portion of the shift arm 57 is a cam follower element 5Spositioned for engaging the angular surface of the shift cam 45 on thedriving member 37. The forward end portion of the shift arm 57 isprovided with an elongated hole 59 for pivot connection with a pin 60,the pin 60 being rigidly mounted on the transversely slidable plate ofthe mo'tor 24 on the driven member 15. The pin 60 should be of suchdiameter that it be in close slidable tolerance with respect to the hole59. The purpose of the hole 59 being elongated is to take up the lostmotion between the transversely slidable motor'24 and the arcuatemovement of the shift arm 57 about the pivot pin 23 on the lug 20.

In order to .urge the cam follower element 58 on the shift arm 57 in adirection toward engagement with the shift cam 45 on the driving member3 7 a tension spring 61 is anchoredfon one end to the base 11 at'62 andthe other'end thereof being anchored to the shift arm '57 Now for thepurpose of urging the driven member .15 in a rearward or retractivedirection toward the stop pins 16 and 17, a compression spring 64 isanchored on one end to the base 11 and the other end in operativeengagement with the driven member 15 as illustrated in each of thedrawings. Thus the driven member is always -urged in a retractivedirection by the spring 64.

Having thus described the construction of a preferred embodiment of theinvention, the operation thereof will now be described.`

Operation Figure l illustrates the position of the'mechanism of thisinvention in therretracted or starting position.

The motor 24 is rst energized from a source of energy to cause rotationof the rotatable element' 26 thereof with the boring element 28. Themotor 2 4 may for convenience be energized continuously. Next theworkpiece 65 is secured rigidly in the required position. Theconventional control means is then operated to energize the cylinder 29by Vintroducing fluid under pressure from a source thereof into thechamber 34 through the conduit 36 to start the cycle of operation. Theiluid pressure acting onthe piston 31 advances the work member 32 andthe driving member 37 in a forward direction. The

notch Y50 of the finger 46 carried by the driving member 37 immediatelyengages the shoulder 21 of the lug 20 in driving relation thus advancingforwardly the driven member 15. The boring element 28 carried by thedriven member 1.5 advances to engage the workpiece 65. The cylinder 29therefore advances both the driving member 37 and the driven member 15to borevthe first bore 66 in the workpiece 65 whereby the mechanism ofthe invention reaches a first release position illustrated inV Figure 2.

From Figure 2 it will be seen that the cam 52 of the nger 46has engagedthe cam pin 53, thereby moving the finger 46 arcuately about the pivot48 in a clockwise direction which disengages the notch 50 from theshoulder 21. The driven member 15 now being disengaged is movedretractively by the spring 64 lto withdraw the-boring element `28 fromthe bore 66 of the workpiece 65 whereby vthe Amechanism of the inventionreachesfthe position'illustrated in Figure 3; .It should be'noted thatthe driving member 37 is-'advancingprogressivelyV from the initialposition shown in Figure 1 Y The retractive movement of the drivenmember 15 from the position shown in Figure 2 to the position showninFigure 3, causes the cam follower 'element 58 on the shift arm 57 toengage the shift cam 45 of the driving member 37 which angularlydisplaces the shift arm 57 about the pivot 23 in a counter-clockwisedirection. This rotative movement of the shift arm57 moves the motor 24and its associated plate 25 from the leftward position shown in Figuresl and 2 to the alternate rightward position shown in Figures 3 and 4inthe driven member 15.

The cylinder 29 continues to advance ina forwardly direction to engagethe notch 51 of the finger 47 with the shoulder 22 of the lug 20 indriving relation which again advances forwardly the driven member 15 tobore the second -bore 67 in the workpiece 65 whereby the mechanism ofthe invention reaches a second release position illustrated in Figure 4.

When the cylinder 29 has advanced the driving member 37 to the secondrelease position as explained above, the cylinder 29 is ythen energizedin the reverse direction which returns the driving member 37 to itsretracted position and the spring 64 retracts the driven member 15 towithdraw the boring element 28 from the second bore -67 ofthe workpiece65 to the initial Aori starting position -shown in Figure l. It willbeseen that when the cylinder 29 is fully retracted the caml followerelement 58 of the shift arm 57 becomes disengaged from the shift cam-45ofthe driving member 37 whereby the urging of the spring 61 angularlydisplaces the shift arm 57 about the pivot 23v in a clockwisedirection.V This clockwise movement of the shift arm 57 shifts themotor. 24 with its associated plate 25Y leftwardly in the groove 19ofthe Vdriven memberv15to return the boring element 28 to theinitialposition shownin Figure l. Thus a'cycle of operation has beencompleted whereby two juxtaposed boresf66 and 67 have-.been made in theworkpiece in a single stroke ofY the cylinderl 29.

It will be observed in Figure 4 that when the cylinder 29 has advancedthe driving member 37 to the secondV release position, the trip plate 40engages the actuating lever 44 of themicroswitch 43 which in turnactuates a conventional control valve arrangement to reverse theoperation of the cylinder 29 thus returning the mechanism from theposition shown in Figure 4 to that shown in Figure 1 automatically.Y Ofcourseit should be understood that retraction of the cylinder 29 mayalso be accomplished -bymanual control-if desired.`l However, when themechanism of this -invention is .employed in multiple stage turretoperation as described previously, the movement of the turret canautomatically start the boring cycle when the workpiece reaches toproper position as illustrated. K

At this point it should be obvious to one skilled in the art that thedistance between centers of the bores 66 and having a longitudinally'disposed track thereon, a driven niemberslidably disposed in theforwardp'ortionof. said track, stop means mounted on said basepositionedto' limit rearw'ardmovement of said driven member, a lugrigidly connectedA tosaid driven member and extending rearwardly inspaced relation with respect to saidtrack, said lug having' a firstshoulder disposed on therearward portion thereof and a second shoulderdisposed laterally of said iirst shoulder, said drivensmember having agroove positioned transversely thereon, a motor having a rotatableelement supported in said groove of lsaid first member in slidablerelation, said rotatable element havingits axis of rotationlongitudinally positioned, a boringel'ementfremovably connected to saidrotatable elementland extending forwardly of said driven memberpositioned to engage said workpiece, a driving member slidablyy disposedin the rearward portion of said track, a double acting fluid pressureoperated cylinder mounted on the rearward portion of said base andhaving a reciprocable. work member thereon, said work member beingdrivingly connected to said Vdriving member in operative relation, ashift cam mounted on the forward portion of said driving member, a shiftarm pivotallyconnected to. sa'id motor and said lug and extendingrearwardly thereof, a Vcam follower element disposed on therearwardportion of said shift arm positioned to engage said.cam forshift'- ing'said motor laterally from an initial position to analternate position, a first spring mounted on said base.; positioned Vtourge said cam follower element of. said shift arm toward saidY cam, safirst finger pivotallyY Amounted on; one sideV of said driving member'and `ex-' tending" forwardly thereof,- alsecond iinge'rpivotallymounted on, the other side Aof said driving member and extending'forwardly thereof,` a' second sp'ring .connected to urge said fingers,toward each other, `said=first nger having a first notch on the forwardend portion thereof Y positioned to engagesaid firstv shoulderof `s`aidlug :in

67 is directly related as a function of the length of the shift arm 57and the position of the pivot 23 thereon with respect tothe longitudinalposition of the pivot 23 on the lug 20.A The depth of the bores 66 and67 is governed by do not depart from the spirit of the invention norfrom.v

the scope thereof as defined in the What is claimed is: l,

1. A machine ixturefor sequentially boring a pair of parallel disposedbores in a workpiece` comprising a base appended claims.

driving relation, aiiirstcam positioned on the forward" end portion ofsaid lrstniinger, a first campin mounted on said base positioned `toengage said first cam forilis-` engaging said rst finger-from saidiirstyshoulder of vsaid lug when said driving member is moved forwardlyfrom; an initial retracted position to a predetermined first releaseposition, said second finger having a second notch on the forward endportion thereof positioned to engagev said= second shoulder yof saidlugin driving relation, said second notch being positioned rearwardly ofsaid first notch, a second cam positioned on the forward end portion ofsaid second nger, a second cam pin mounted on said base positioned toengage said second cam'for disengaging lsaid second finger from saidsecond shoulder'of said Vlug when said driving member is moved forwardlyfromL lug thereby moving saidV driven member forwardly to said firstrelease position for/boring a first bore in saidf workpiece, said drivenmember with said shift arm subsequently moving retractively to engagesaid cam 'follower element with said shift cam for shifting said motortrans-1 versely in said groove to said alternate position, said cylindermoving said driving member fronrsaid "rst release position to engagesaid second fingerwith said lug for moving saidrdriven member to asecond release position for boring a second bore in said workpiecejuxta- Vposed to said rst bore, and means for energizing said cylinderin the other direction to return said driving mem-y ber to saidretracted position. v

-- 2. Ajmachinexture for sequentiallyv boring a; y

of parallel '.dispsed. bores 'in a workpiece comprising-a '7 base, adriven member reciprocable in a longitudinalfdirection supportedon saidbase, stop means mounted on said base positioned to limit rearwardmovement of said driven member, a 'lug mounted on the rearward side ofsaid driven member, said lug having a first shoulder disposed on thel'rearward portion thereof and a second shoulder disposed laterally ofsaid rst shoulder, said driven member having -a groove positionedtransversely thereon, a motor having a rotatable element slidablysupported in said groove, said rotatable element having its aXis ofrotation positioned longitudinally, a boring element connected tosaid'rotatable element and extending forwardly thereof positioned toengage said workpiece, a reciprocable driving-member supported on saidbase in axial alinement withlsaid driven member, a uid pressure operatedcylinder'mounted on said base and having a reciprocable work memberthereon, said Work member being drivingly connected to said drivingmember in operative relation, a shift cam mounted on the forward portionof said driving member, a shift arm pivotally connected to said motorand said lug and extending rearwardly thereof, a cam follower elementdisposed on the rearward portion of said shift karm positioned to engagesaid cam for shifting saidrnotor laterallyfrom an initial position to analternate position, a first spring mounted on said base positioned tourge said cam follower element toward said cam, a first finger pivotallymounted on one side of said driving member and extending forwardlythereof, a second finger pivotally mounted on the other side of saiddrivingzmember and extending forwardly thereof, a second springconnected to urge said fingers toward each other, said first fingerhaving a first notch on the forward end portion thereof positioned toengage said first shoulder in driving relation, a first cam positionedon the `forward end portion of said first finger, a first cam pinmounted on said base positioned -to` engage said first cam fordisengaging said rst finger from said first, shoulder whensaid drivingmember is moved forwardly from a retracted position to a predeterminedfirst release position, said second finger having a second notch'on theforward end portion thereof positioned to engage said secondI shoulderin driving relation, said second notch being positioned rearwardly ofsaid first notch, a second cam positioned on the forward end portion ofsaid secondiifnger, a second cam pin mounted on said base posi- .tionedto engage said second cam forA disengaging said second finger from saidsecond shoulder when said driving member4 is moved forwardly from saidfirst release position to.a predetermined second release position, athird spring-:mounted on said base positioned to urge said driven memberrearwardly, a source ofenergy connected to. energize. said motor forrotating said boring element, a source; of uidunder pressure connectedto energize controllably said cylinder to move progressively forwardsaidgdriving member'from a retracted position to engage, said first ngerwith said lug thereby moving said driven member forwardly to said firstrelease position for boring a. first, bore in said workpiece, saiddriven member with said shift arm subsequently moving retractively toengage said cam follower element with said shift cam for shifting saidmotor transversely in said groove to said alternate position, saidcylinder moving said driving member' from said first release position toengage said second finger with said lug for moving said driven member toa second release position for boring a second bore insaid workpiecejuxtaposed to said first bore, and means for moving said driving memberto a retracted position.

3f. A machine fixture for sequentially boring a pair of paralleldisposed bores in a workpiece comprising a base, a driven memberreciprocable in a longitudinal direction supportedon said base, stopmeans mounted on said base positioned to limit rearward movement of saiddriven member, a lug mounted on the rearward side of Said drivenmemben'said lug having a first shoulder disposed, 'onrthe v.rearwardportion thereof and a second shoulder disposed laterally iof said firstshoulder, said drivenmember having-a groove positionedtransvers'elythereon, a motor-having a rotatable element slid'ably supported in saidgroove, said rotatable element having its axis of rotation positionedlongitudinally, a boring element connected to said rotatable element andextending forwardly thereof positioned to engage said workpiece, areciprocable driving mem-ber supported-on said base in axial alignmentwith said driven inem-l ber, power means mounted on said baseoperatively connected to reciprocate controllably said driving member, ashift cam mounted on the forward-portion ofv saiddriving member, a shiftarm pivotally connected to said motor and said lug and extendingrearwardly thereof, a cam follower element disposed on the rearwardportion of said shift arm positioned to engage said cam for-shiftingsaid motor laterally from an initial position tok au alternate position,a 'first spring mounted on said base positioned to urge said `camfollower element toward said cam, a first linger pivotally mounted onone side of said driving member and extending forwardly thereof, asecond finger pivotally mounted on the other sideof said drivingv memberand extending forwardly thereof, a second spring connectedto urge saidfingers toward each other, said 4first finger being positioned to engagesaid ist shoulder in driving relation, a first cam positioned' on theforward end portion of said first finger, a first cam pin mounted onsaid base positioned to engage said first cam for disengaging said firstfinger from saidfirst shoulderrwhen said drivingV member is movedforwardly from a retracted position to a predetermined first-releaseposition, said second-finger being positioned to engage said secondshoulder in driving relation when said first finger is disengaged vfromsaid firstl shoulder, a ,second cam positioned on the forward endportion of said second finger, a second cam pin mounted on said basepositioned to engage said second cam for disengaging said second' fingerfrom said second shoulder when said driving member is moved forwardlyfrom said first release position to a second release position, a thirdspring mounted on said base positioned to urge said driven memberrearwardly, a source of energy connected to energize said motor forrotating said boring element, said power means being controllable tomove progressively forwardy saiddriving member from a retracted positionto engage said first finger with said lug thereby moving said drivenmember forwardly to said first release position for boring a `first borein said workpiece, said driven member with Vsaid shift arm subsequentlymovin-g retractively to engage said cam follower element with said shiftcam for shifting said' motor transversely in said groove to saidalternate posifrom, said power meansimoving said driving member fromsaid first release position to engage said second finger wlth said lugfor moving said driven member -to a second release position for boring asecond bore in'said workpiece juxtaposed to said first bore, and meansforv moving said driving member to a retracted position.

4. A machine fixture. for sequentially boring a pair of paralleldisposed bores. in a workpiece Vcomprising a base, a drivenmemberreciprocable in a longitudinal direction supported on said base, afirst shoulder disposed onone side of said driven member and a secondshoulder disposed on the other side of said member, said driven memberhaving a groove positioned transversely thereon, `a motor having arotatable element slidabl-yI lsupported in said .gro-ove, said rotatableelement having its axis of rotatlon positioned longitudinally, a boringelement connected to saidl rotatable element and extending forwardlythereof positioned to engage said workpiece, Va reciprocable drivingmember supported on said base in axial alinement with said drivenmember, power means mounted on said base operatively connected toreciproca-te .Controllably said driving member, a shift Vcam mounted onthe Yforward portion of' said driving member, a shi-ftrarm pivotallyconnected-to said motor and' said driven mem-l ber and extendingrearwardlyfthereof, ra` cam follower element disposed on the rearwardportion of said shaft arm positioned to engage said cam forshifting saidmotor laterally from an initial position to an alternate position, afirst spring mounted on said` base positioned to urge said cam followerelement toward said cam, -a first finger pivotally mounted on one sideof said drivingmember and extending forwardly thereof, a second fingerpivotally mounted on the other side of said driving member and extendingforwardly thereof, a second spring connected to urge said fingers towardeach other, said hrst finger being positioned to engage said firstshoulder in driving relation, a first cam positioned on said firstfinger, a first cam pin mounted on said base positioned to engage saidfirst cam vfor disengaging said first finger fromsaid rst shoulder whensaid driving member is moved forwardly from a retracted position to apredetermined first release position, said second finger beingpositioned to engage said second shoulder in driving relation when saidfirst finger is disengaged from said first shoulder, a second 'campositioned on said second finger, a second cam pin mounted on said basepositioned to engage said second ,cam for disengaging said second fingerfrom said second Y 10 positionedton said 'second'fingen second cani vpinmounted on said base positioned to engage said second cam fordisengaging said second finger from said driven member when saidvdriving member is moved forwardly toga second release position, a thirdspring mounted on said base positioned to urge said driven memberretractively, a source of energy connected to energize said motor, saidpower means being controllable to move progressively forward saiddriving member 'from a retracted position to 'engage said first fingerwith said driven member to a first release position for boring a firstbore in said workpiece, said driven member with said shift armsubsequently moving retractively to engage said cam follower elementwith said shift cam for shifting said motor transversely in said grooveto said alternate position, said power means moving said driving memberA from said first release position to engage said second finger withsaid driven member for moving said driven member to a second releaseposition for boring a second bore in said workpiece juxtaposed to saidfirst bore, and

- means yfor retracting said driving member.

shoulder when said driving member is moved forwardly to a second releaseposition, a third spring mounted on said base positioned to urge saiddriven lmember retractively, a source of energy connected to energizesaid motor for rotating said boring member, said power means beingcontrollable to moveprogressively forward said driving member from aretracted position to engage said .first finger with said driven memberthereby moving said driven memberk forwardly to said rst release'position for boring a first bore in said workpiece, said driven memberwith said shift arm subsequently-moving`retractively to engage said camfollower element'with said shift .cam for shifting saidmotortransversely in said groove to said alternate position, said power.means moving said driving member from Asaid first 'release positionfto,engage said second finger with said driven memberrfor moving saiddrivenmember to a second release position for boring a second boreinsaid workpiece juxtaposed to said first bore,rand means for movingVsaid driving member to a retracted position. Y A

' 5. A machine fixture -for sequentially boring a pair of paralleldisposed bores in a workpiece comprising `a base, a driven memberreciprocable in a longitudinal `direction supported on Vsaid base, saiddriven vmember hav; img a groove positioned transversely thereon,afmotor having a rotatable element slidably ksupported in said groove,said rotatable element having its axis of rota-Y tion positionedlongitudinally, arboring element connect1 edto said rotatable elementpositionedv to engage Vsaid workpiece, a reciprocable driving membersupported on saidbase in axial alinement with said drivenmember, powermeans mountedon said base operatively connected to reciprocatecontrollably said driving member, a shift cam positioned on said drivingmember, a shift arm pivotally connected to said motor and saiddrivenmember, acam follower element disposed ongsaid shift arm po' sitioned tofeng'age Vsaid 'cam for shifting said motor laterallyfrom an initialposition to yan alternate position, a-first spring mounted on saidbasepositioned vto'urge saidcam follower element toward said cam, al1irst'fin ger and a second finger pivotally` mounted on said` drivingvmember, a second spring connected to urge said fingers toward eachother, said first finger being positioned to engage said driven memberin driving'relation, a first camY positioned on said first finger, afirst cam pin mounted on said base positionedto-engage saidfirst cam fordisengaging said first finger from. said driven member when said drivingmem-ber is movedmforwardly from aretracted position to a predeterminedfirst release posi-v tion, saidf'second finger beingpositioned to engagesaid driven membrin driving 'relation when said first fingerVisg'disen'gaged from said. driven member, a second cam Y 6. A machinefixture for sequentially boring a plurality of bores in a workpiececomprising a base, a driven member reciprocable in a longitudinaldirection supported on said base, said Idriven member having a groovepositioned transverselythereon, a motor having a rotatable elementslidablylsupported inV said groove, said rotatable element having itsrotational axis positioned longitudil nally,ra boring element connectedto said rotatable element positionedV to engageA said workpiece, areciprocable driving member supported on Vsaid base in axialaline- Yment with said driven member, power means mounted on said baseoperatively connected to reciprocate controllably said driving member, ashift cam positioned on saidY driving member, a shift arm pivotallyconnected to said motor and said driven member, a cam follower Y elementdisposed on said shiftV arm positioned to engage said cam for shiftingsaid motor laterally from one position 4to van alternate position,resilient means mounted onsaid fixture positioned to urge said cam'follower element toward. said ca-m, a first finger and a second fingerpivotally mounted on said driving member, yieldable means connected tourge said fingers toward each other',

said first finger beingpositioned to engage said driven member indriving relation, a first cam positioned on said first finger, arfirstcam pin mounted on lsaid'base positioned to engage said first cam fordisengaging said rst finger from said driven member when said drivingmember s moved forwardly -from va retracted position to a predeterminedfirst release position, said second finger being positioned to engagesaid driven member in driving relation when said first finger isdisengaging from said driven member,I a second cam positioned on saidsecond finger, a second cam pin mounted on said base positioned toengage said second cam for disengaging said second finger from saiddriven member when said driving member ismoved forwardly to a'secondrelease position, means mounted on said base for urging said drivenVmember retractively, a source of energy connected to energize saidmotor, said power means being controllableto move progressively forwardsaid driving member Vfrom a re-V tracted position to engage said first4finger with said driven member to said first. release position forboring a first bore in qsaid workpiece, said driven member with saidshift arm subsequently moving retractively to engage said cam followerelement with said shift cam Afor shifting said motor transversely insaid groove to said alternate posi 4 tion,` saidkpower means Vmovingsaid Ldriving member from 'said first Yrelease' position to engage saidsecond fin'- ger with'said driven member for moving saidpdriven mem-`ber to a second release position for boring a second bore in saidworkpiece, and means yfor retracting said driving member,

' 7. AA machine fixture for sequentially boring a plurality f i berreciprocable in a longitudinal direction supported on said base, aYmotor mounted for substantially transverse movement on said drivenmember, a `boring element connected in driven relation to said 'motorand positioned to engage said workpiece, means on said base positionedto urge said driven member rearwardly, a reciprocable drivingA membersupported on said base in axial alinement with said driven member, powermeans mounted onsaid base operatively connected to reciprocatecontrollably said driving member, a shift cam on said driving member, ashift arm pivotally mounted on said driven member and connected to saidmotor, a cam follower element disposed on said shift arm positioned toengage said cam for shifting said motor from one position to analternate position, resilient mea-ns mounted on said fixture positionedto. urge said follower element toward said cam, a first finger andasecond finger pivotally mounted on said driving member, yieldable meansconnected to urge said fingers in one direction, said first finger beingpositioned toy engage said driven member in driving relation, a firstcam positioned on said first finger, a first cam pin mounted on saidbase positioned to engage said first cam for disengaging said firstfinger from said driven member when said driving member is lmovedforwardly from a retracted position to a predetermined first releaseposition, said second finger being positioned to engage said drivenmember in driving relation when said first finger is disengaged fromsaid driven member, a second cam pin mounted on said 'baserpositioned toengage said second cam for disengaging said second finger from saiddriven member when said driving member is moved forwardly to apredetermined second release position, a source fof energy connected toenergize said motor, said power means being controllable to moveprogressively forward said driving member from -a retracted position toengage said first finger with said driven member to saidv first releaseposition for boring a first bore in said workpiece, said driven memberwith said shift arm subsequently -moving retractively to engage saidfollower element with said shift cam for shifting said motor insubstantially a transverse direction to said alternate position, saidpower means moving said driving member from said first release positionto engage said second finger with said driven member for moving saiddriven member to said second release position for boring a second borein said 1workpiece, and means for retracting said driving member.

8. A machine fixture for sequentially boring a plurality of bores in aworkpiece comprising a base, a driven member reciprocable in alongitudinal direction supported on said base, a motor mounted forsubstantially transverse movement on said driven member, a boringelement driven by said motor positioned to engage said Workpiece, meanson said base positioned to urge said driven member retractively, aldriving member supported on said base, power means mounted on said baseoperable to move said driving member, shift means mounted on saidfixture adapted to move said motor from one position to an alternateposition when said driving member is moved to a predetermined firstrelease position, a first nger and a second finger pivotally mounted onsaid `driving member, yieldable means connected to urge said fingers inone direction, said first finger being positioned to engage said drivenmember in driving relation, a first cam positioned on said first finger,a first cam pin mounted on said base positioned to engage said first camfor disengaging said first finger from said driven member when saiddriving member is moved forwardly from a retracted position to saidpredetermined first release position for boring a first bore in saidworkpiece, said second Enger beingk positioned to engage said ydrivenmember in driving relation when said first finger is disengaged fromsaid driven member, a second cam positioned'onjsaid second finger., alsecond `cam pin mounted on said base positioned to engage said secondcam for disengagiug said second finger from said driven member when saiddriving member is moved from said first release position to `apredetermined second release position for boring a second bore in saidworkpiece, asource of energy connected to said motor, said power meansbeing controllable to move progressively forward said driving memberfrom ya retracted position to engage said first finger with said drivenmember to said first release position, said driven member subsequentlymoving retractively to engage said shift means for moving said motor tosaid alternate position, said power means moving said driving memberfrom said first release position to engage said second nger with saiddriven member for moving said driven member to said second releaseposition, and means for retracting said driving member.

9. A machine fixture for sequentially boring a plurality of bores in aworkpiece comprising a base, a driven member reciprocable in alongitudinal direction supported on said base, a motor mounted forsubstantially transverse movement on said driven member, a boringelement driven by said motor and engageable with said workpiece, asource of energy connected to said motor, resilient means on said basepositioned to normally urge said driven member retractively, a drivingmember slidably supported on said base for longitudinal reciprocationtoward and away from said driven member, power means mounted on saidbase for moving said driving member through a predetermined longitudinalstroke distance, shift means mounted on said fixture for moving saidmotor laterally from one position to an alternate position when saiddriving member is advanced to a first release position intermediate theextremes of said stroke distance, releasable means mounted on one ofsaid members and positioned for engaging drivingly the other saidmember, means for releasing said releasable means from engagement Withsaid other member when said driving member is advanced to said firstrelease position for permitting subsequent retractive movement of saiddriven member, said releasable means being adapted to re-engagedrivingly the other said member when said driving member isadvancedlongitudinally #beyond said first release position, and means forretracting said driving member when the driving member has completed itsfull stroke distance movement. Y

10. A machine fixture for sequentially boring a plurality of bores in aworkpiece comprising a base, a driven member reciprocable in alongitudinal direction and slidably supported on said base, a boringelement mounted on said driven member for lateral movement With respectthereto and for engagement with said workpiece, means on said base foi`normally urging said driven member retractively, -a driving membersupported on said base for longitudinal movement toward said drivenmember, power means mounted on said base for moving said driving memberlongitudinally through a predetermined stroke distance, shift meansmounted on said fixture for moving said boring element laterally Ionsaid driven member from one position to an alternate position When saiddriving member is advanced to a first release position, releasable meansmounted on one of said members and positioned fo-r normally engagingdrivingly the other said member, means for releasing said releasablemeans from engagement with said other member when said driving member isadvanced to said first release position for permitting subsequentretractive movement of said driven member, said releasable means beingadapted to re-engage drivingly the other said member when said drivingmember is advanced beyond said first release position, and means forretracting said driving member upon. completion of its predeterminedlongitudinal stroke movement.

References Cited in the file of this patent UNITED STATES PATENTS

